The seventh Earl of Lucan disappeared after the body of Sandra Rivett, nanny to his three children, was found at the family home at 46 Lower Belgrave Street in central London on November 7 1974.

Here are some of the countless theories about what became of the aristocrat:

• Lady Lucan said at the time of the incident that her husband admitted committing the crime and had said it was a mistake. It has also been reported that she believes Lucan jumped to his death off a ferry leaving Newhaven, East Sussex.

• Lucan’s car was found abandoned and soaked in blood in Newhaven and an inquest jury declared the wealthy peer the killer a year later.

• The first reported sightings of Lucan occurred soon after the murder. In January 1975 he was supposedly spotted in Melbourne, Australia, and five months later he was apparently in Cherbourg and St Malo, France.

• He was apparently spotted in Cape Town, Mozambique and then Bulawayo. Police in Cape Town went so far as to check fingerprints on a beer glass, reputedly held by the peer.

• Scotland Yard asked Barbados police to investigate a report in 1978 that a British resident there was sending money to Lucan in South America.

• He has also been reportedly sighted on an ex-Nazi colony in Paraguay, at a sheep station in the Australian outback, backpacking on Mount Etna and working as a waiter in San Francisco, and one couple reported seeing him in a private hospital in Johannesburg in 1995.

• There were even claims that he fled to India and lived life as a hippy called “Jungly Barry”.

• In 1987, journalist Sally Moore published Lucan - Not Guilty, a book that claimed an intruder murdered the nanny and attacked Lady Lucan.

• He was officially declared dead by the High Court in 1999 but reported sightings of him continued to be made around the world.

• An ITV drama based on John Pearson’s book The Gamblers claimed Lucan’s high-rolling friends, who included Sir James Goldsmith and John Aspinall, spirited him out of the country after the murder.

• In 2007 the hunt for Lucan was focused on the small New Zealand township of Marton after claims that he may have been living in a car there.

• In 2012, Lucan’s brother Hugh Bingham said he was “sure” the missing peer fled to Africa following the nanny’s murder. But he then said he was unsure if his sibling was alive or dead.

• In Dead Lucky, former senior Scotland Yard detective Duncan MacLaughlin said that Lucan fled to Goa where he lived a hippy lifestyle as Barry Halpin until his death in 1996.

• Some say he was held to ransom by the IRA or shot himself and asked that his remains should be fed to the tigers at the zoo in Kent, which belonged to Mr Aspinall.